feat: Auto-generate example sidebar and fix directive default

- Restructured the example documentation to use autogenerated sidebars based on the directory structure. This makes the sidebar easier to maintain.
- Added `_category_.json` files to provide proper labels for the generated sidebar categories.
- Fixed a bug where the `%%RESIST%%` directive without parameters did not default to `abx=auto` and `org=auto`.
- Removed the obsolete `e_coli.mdx` page.

Author: Uli-Z

…cs/pneumonia-demo/community-acquired.mdx …ocs/1-live-demo/1-community-acquired.mdxexample/docs/pneumonia-demo/community-acquired.mdx renamed to example/docs/1-live-demo/1-community-acquired.mdx example/docs/pneumonia-demo/community-acquired.mdx renamed to example/docs/1-live-demo/1-community-acquired.mdx

@@ -0,0 +1,4 @@
+{
+  "label": "Live Demo: Pneumonia Treatment",
+  "position": 1
+}

…ocs/pneumonia-demo/hospital-acquired.mdx …docs/1-live-demo/2-hospital-acquired.mdxexample/docs/pneumonia-demo/hospital-acquired.mdx renamed to example/docs/1-live-demo/2-hospital-acquired.mdx example/docs/pneumonia-demo/hospital-acquired.mdx renamed to example/docs/1-live-demo/2-hospital-acquired.mdx

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+{
+  "label": "Feature Examples",
+  "position": 2
+}

…cs/pneumonia-demo/specific-pathogens.mdx …ocs/1-live-demo/3-specific-pathogens.mdxexample/docs/pneumonia-demo/specific-pathogens.mdx renamed to example/docs/1-live-demo/3-specific-pathogens.mdx example/docs/pneumonia-demo/specific-pathogens.mdx renamed to example/docs/1-live-demo/3-specific-pathogens.mdx

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+{
+  "label": "Test Cases",
+  "position": 3
+}